This invention relates to semiconductor memory devices, memory chips, memory modules, and the handling of defective memory components.
Due to the yield limitation of semiconductor fabrication process, a semiconductor memory wafer usually contains defective memory devices. As the cell density of the semiconductor device increases, it is becoming harder to achieve high production yield.
During the device fabrication process, certain repairing process may be used to replace defective rows or columns in the memory cell array. However, there is a limit as to the capability of such repairing process. Some memory devices remain defective at the semiconductor die level after the fabrication process.
To repair the memory devices above the die level is a complex issue regarding the feasibility, efficiency, and performance.